Electrical gas-lamp.



F. SKAUPY.

ELECTRICAL GAS LAMP. APPLICATION FILED MAYIZ. 1914.

14200,?70. Patented Oct. 10,1916.

WITNESSES INVENTOR W 6 FRANZ SKAUPV ATTORNEYS PTENT OFFICE.

AKTIENGESELLSCHAFT (AUERGESELLSCHAFT), 0F BERLIN, GERMANY, A

PORATION or GERMANY.

COR-

ELECTRICAL GAS-LAMP.

Specification of Letters Patent.

Patented oct. to, 1916.

Application filed May 12, 1914. Serial No. 837,998.

To all whom it may concern.-

Be it known that I, FRANZ SKAUPY, citizen of the Empire of Austria-Hungary, re-

siding at Berlin, Germany, have invented certain new and useful Improvements in Electrical Gas-Lamps, of which the following is a specification.

My invention relates to electrical gas lamps filled with rare gases of the atmosphere, such as neon or helium, in which illumination is produced by an are light type of discharge. Such lamps are usually provided with electrodes or at least cathodes of very reactive electropositive metals especially alkali metals or alloys of same. Such lamps may be used in the usual electric circuits of 100 to 220 volts, and may have convenient dimensions; thus, 6. g., a lamp on 220 volt circuit and having a tube of 15 mm. diameter requires a length of only. 600 mm. between cathode and anode. Between the electrode receptacles and the tube proper of these lamps, inserts may be provided to prevent the penetration of the electrode ma terial intothe tube. I

The object of my invention is to improve the lamps aforesaid by the use, for the electrodes, of alloys of alkali metals with either thallium, mercury or lead, or at least to use such alloys for the cathode. These metals, for the purposes of the invention and as contrasted with the alkali metals referred to, I term heavy metals. A sufiicient quantity of the said metals is added to the alkali metals so that the softness of the alkali metals is retained and that the temperature of fusion is not too much increased and so that detaching and expelling the clinging and occluded gases is not ren cred too diificult. The alloys of sodium wit I thallium or mercury (for instance 30% thallium with 70% sodium or 40% mercury with 60% sodium) have proved very satisfactory. With the addition of thallium it ispossible tooverstep without obtaining too high a temperature of fusion. It is also possible to alloy alkali metals with one or more heavy metals, or with heavy metals and mercury,

as e. 9., sodium with potassium and lead (e. g. 50% sodium, 20% potassium and 30% lead) or sodium with mercury and lead (6. g. 50% sodlum, 40% mercury and 10% lead).

In combining alkali metals and heavy metals to form alloys within the scope of the lnvention -I prefer that their melting polnt should not exceed 200 C.' and that the percentage of heavy metal contained in the alloy should not be less than 10%. 7

Alloys as described are less liable to catch fire as they do not react with water in the energetic manner displayed by pure alkali metals. very important advantage is obtained as the lamps can easily be operated by currents less than 0.8 amp.

The annexed drawing shows an elevatio of an electrical gas lamp, in which the cathode is of an alloy as above mentioned.

a, shows the light giving tube, 6, the cathode made of the new alloy and c the anode; d and 6 represent the leading-in wires to the cathode b and to the anode a respectively.

f is the cathode receptacle with an insert that prevents the particles thrown of the cathode from entering the tube proper. The receptacle 7 is made of glass diflicult of fusion as, e. 9., borosilicate glass containing a small amount of alkali such as Jena combustion glass. 7

I claim:

1. In an electrical gas lamp having a light space filled with a rare gas, an electrode consisting of an alloy of alkali metal and heavy metal.

2. In an electrical gas lamp having a light space filled with a rare gas, a cathode receptacle and a cathode therein consisting of al-. kali metal and heavy metal said alloy being more inert as to said receptacle than is the alkali metal itself. 7

. 3; Inan electrical gas lamp'having a light With the use of mercury another space filled with a rare gas, an electrode conconsisting of an alloy of alkali metal and heavy metal the melting point of said alloy comprising an alloy of alkali metal with not being not greater than 200 C. less-than 10% of heavy metal. 1

5. In an electrical gas lamp having a light In testimony whereof I aflix my signature space filled with a rare gas, an electrode in presence of two witnesses.

5 consisting of an alloy of alkali metal with FRANZ SKAUPY.

thallium. Witnesses:

6. In an electrical gas lamp having a light IVOLDEMAR HAUPT,

space filled with a rare gas, an electrode HENRY IIASPER. 

